Wow this art is incredible enduring! Did you draw it all yourself? I love the Yoshi's Island aesthetic.
The level design was good but I felt very out of control when I had the tornado power-up. It was unclear how the tornado ends, and I think by the end of the game I realized it's based on a timer. The tornado was fun at first, but it's frustrating when there's spikes or pits around because you're just screwed sometimes. The spikes felt very unforgiving because they're tough to avoid with such a short jump. This in combination with the long stretch without a checkpoint makes the first half of the game a little tedious with forced backtracking.
If you focus on being more forgiving with the player I think you'll have something really cool here! I'd love to see more of the digging mechanic.